Narrative:

While operating on Y808 to onion intersection and in radar contact with tokyo control; we encountered a line of thunderstorms ahead. We asked tokyo for an initial left turn to avoid this weather near the route of onion to kalna intersections. We were cleared to deviate up to 50nm left of course for weather deviation. We were subsequently cleared to deviate up to 60nm left of track. A few minutes into our deviation; we were asked to contact tokyo radio to continue via cpdlc communications. As we approached kalig intersection and correcting back on course after weather deviation; we received several cpdlc text messages asking for a position report and one message confirming our cleared routing (which we were following). Apparently as we had deviated so far to the left around the weather; the FMC had failed to show that we had passed the fix of onion; which we had passed some 50 nm to our right. It also appeared that tokyo control had failed to notify the oceanic controllers of our deviation prior to our handoff. We used text communications via cpdlc to give a position report; (eta to kalig; flight level and next reporting point.) although we never deviated from the from our cleared route except to go around weather with tokyo center's permission; it appeared that the oceanic controller was confused of our routing during our weather deviation.

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Original NASA ASRS Text

Title: B747 pilot reported he was questioned on his routing by Tokyo ATC while deviating around thunderstorms.

Narrative: While operating on Y808 to ONION Intersection and in radar contact with Tokyo Control; we encountered a line of thunderstorms ahead. We asked Tokyo for an initial left turn to avoid this weather near the route of ONION to KALNA intersections. We were cleared to deviate up to 50nm left of course for weather deviation. We were subsequently cleared to deviate up to 60nm left of track. A few minutes into our deviation; we were asked to contact Tokyo radio to continue via CPDLC communications. As we approached KALIG intersection and correcting back on course after weather deviation; we received several CPDLC text messages asking for a position report and one message confirming our cleared routing (which we were following). Apparently as we had deviated so far to the left around the weather; the FMC had failed to show that we had passed the fix of ONION; which we had passed some 50 nm to our right. It also appeared that Tokyo control had failed to notify the Oceanic controllers of our deviation prior to our handoff. We used text communications via CPDLC to give a position report; (eta to KALIG; Flight level and next reporting point.) Although we never deviated from the from our cleared route except to go around weather with Tokyo Center's permission; It appeared that the Oceanic controller was confused of our routing during our weather deviation.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.